Co-Operative On-Board and Off-Board Component and System Diagnosis and Prognosis

ABSTRACT

A cooperative diagnostic and prognosis system for generating a prognosis of at least one component in a vehicle. An in-vehicle diagnostic unit determines a diagnostic signature of the component each time an occurrence of a condition is triggered and transmits the diagnostic signature to an off-board diagnostic unit. The off-vehicle diagnostic unit determines a SOH of the component and a rate-of-change in the SOH of the component. The off-vehicle diagnostic unit determines whether the rate-of-change in the SOH is greater than a threshold. The off-vehicle diagnostic unit requests additional information from the vehicle in response to the rate-of-change in the SOH being greater than the threshold. The additional information relating to operating parameter data associated with the component. The off-vehicle diagnostic unit receives the requested information and predicts a time-to-failure of the component.

BACKGROUND OF INVENTION

An embodiment relates generally to remote vehicle diagnostics andprognostics.

Vehicles include monitoring systems which utilize sensor data andoperating parameter data for determining whether a component or systemis operating properly. Some controllers within the vehicle includediagnostic which analyze the sensed data and determine the health of asystem. Examples of such systems may include battery monitoring systemswhich may determine the state-of-health of a battery or fuel deliverysystems. In such cases, the vehicle must maintain all sensed data inmemory for analyzing and determining the state-of-health of the systemparticularly if history data is utilized. In such cases, this requiresthat a sufficient amount of memory and sufficient processing power isused to process the data.

Off-board diagnostic and prognostic systems are utilized to remotelydiagnose and predict faults occurring in vehicles. The advantages ofoff-board diagnostic systems are that these systems are not typicallylimited by storage space and can accommodate cooling systems forventilation where high speed processors are utilized. The disadvantageof such systems is that there is a constant transmission of largeamounts of data between the vehicle and the off-board diagnostic systemwhere much of the data may not be utilized. Such a data dump createsinefficiencies and slows down the system.

SUMMARY OF INVENTION

An advantage of an embodiment is the prognosis of a component or systemof a vehicle by cooperatively utilizing both on-board and off-boarddiagnostic units. A degradation signature of a component or system isdetermined by an on-board processor upon an occurrence of a triggeringcondition. The triggering condition may be a time-triggered condition ormay be an event-triggered condition. The degradation signature isdetermined and transmitted to the off-board diagnostic unit each timethe triggered condition occurs. The off-board diagnostic unit determinesand analyzes a state-of-health and either modifies the triggeredconditions (e.g., increasing the frequency for determining thedegradation signature) or requests additional information (e.g.,operating parameter data) for performing a more in-depth analysis of themonitored component/system for determining a prognosis of thetime-to-failure.

An embodiment contemplates a cooperative diagnostic system forgenerating a prognosis of at least one component in a vehicle. Anin-vehicle diagnostic unit determines a degradation signature of the atleast one component each time an occurrence of a condition is triggered.An off-vehicle diagnostic unit receives the degradation signature anddetermines a state-of-health of the at least one component as a functionof the degradation signature. The determined degradation signature ofthe at least one component is wirelessly transmitted to the off-vehiclediagnostic unit upon the occurrence of the triggered condition. Theoff-vehicle diagnostic unit determines a rate-of-change in thestate-of-health of the at least one component. The off-vehiclediagnostic unit determines whether the rate-of-change in thestate-of-health is greater than a threshold. The off-vehicle diagnosticunit requests additional information from the vehicle in response to therate-of-change in the state-of-health being greater than the threshold.The additional information relates to operating parameter dataassociated with the at least one component. The off-vehicle diagnosticunit receives the requested information and predicts a time-to-failureof the at least one component.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram enhanced diagnosis and prognosis system.

FIG. 2 is a flowchart of a method for predicting a time-to-failure.

DETAILED DESCRIPTION

There is shown in FIG. 1 a vehicle 10 in communication with a telematicscenter 12. The vehicle 10 and the telematics center 12 communicatethrough a wireless link. The telematics center 12 is also incommunication with off-board diagnostic unit 14. The off-boarddiagnostic unit 14 monitors and generates a prognosis of at least onemonitored component 15 based on information provided from the vehicle10.

The vehicle 10 includes an on-board diagnostic unit 16 for determining adegradation signature of the monitored component 15. It should beunderstood that although the term “component” is used herein, themonitoring and prognosis may apply to any device, circuit,microcontroller, control unit, sensor, actuator, module, subsystem, orsystem within the vehicle. Degradation signature characterizes andquantifies a size or level of degradation associated with the component.The degradation signature can be represented as a scaled number, avector, a graph, or other like representation. The on-board diagnosticunit 16 is connected to a storage database 18, a plurality of sensors20, control units 22, and analytical tools 24 within the vehicle. Eachof the respective devices coupled to the on-board diagnostic unit 16provide data relating to the operation of the component 15 fordetermining the degradation signature of the component 15. For example,data from sensors may include, but is not limited to, voltages, current,speed, and flow rates. Electronic control units may collect data,diagnostic trouble codes (DTCs), parameter data, or may formulate adiagnosis of a respective component 15 or system which may be used indetermining the degradation signature (e.g., a battery control modulemay determine a state-of-charge of a battery that can be used fordetermining a state-of-health of the battery). In addition, analyticaltools such as diagnostic reasoners may be utilized for identifying thedegradation signature.

The on-board diagnostic unit 16 utilizes data from the variousin-vehicle devices for determining a degradation signature of themonitored component 15. The degradation signature of a component 15 isoften determined by analyzing a current condition of the component 15 incomparison to the component's ideal condition. The specific parametersthat are used to analyze the degradation signature may be specific toeach monitored component 15.

The on-board diagnostic unit 16 determines the degradation signature ofthe component 15 based on a trigger condition. The trigger condition mayoccur in response to a time-triggered condition or an event-triggeredcondition. In a time-triggered condition, the degradation signature isdetermined when a frequency of time or a frequency of the conditionoccurring. That is, the degradation signature is determined based on aperiodic schedule. A periodic schedule may include a straight forwardtiming (e.g., every 72 hours) or may be cyclic (e.g., every n-number ofengine start cycles). Under an event-triggered condition, thedegradation signature is determined based on an occurrence of the event(e.g., whenever the vehicle is started).

After a degradation signature is determined based on the triggercondition, the degradation signature is wirelessly transmitted to theoff-board diagnostic unit 14 via the telematics center 12. Thetelematics center 12 may utilize a wireless communication system thatincludes, but is not limited to, an ad-hoc communication network forrelaying information between the on-board diagnostic unit 16 and theoff-board diagnostic unit 14.

The off-board diagnostic unit 14 includes a storage database 26 forstoring the degradation signature and other information received by theon-board diagnostic unit 16. The off-board diagnostic unit 14 isconnected to a fault model and diagnostic reasoner 28 and otheranalytical tools 30 which assist in isolating the root cause of thefault and facilitating a prognosis of the monitored component 15.

The off-board diagnostic unit 14 receives the degradation signature fromthe on-board diagnostic unit 16 and determines a state-of-health (SOH)of the monitored device. The SOH and associated degradation signatureand data are stored in the storage database 26. The off-board diagnosticunit 14 determines a rate-of-change in the SOH of the component 15. Therate-of-change may include two consecutive received SOH determinations,a selected group of the SOH determinations, or the entire history of thereceived SOH determinations. The rate-of-change is preferably generatedas an absolute value result thereby compensating for negative values.The rate-of-change in the SOH is compared to one or more thresholds. Thevarious thresholds represent the severity of the condition of thecomponent 15, and based on the severity, determinations are made whetheradditional information is required or a modification as to the frequencyin the monitoring of the SOH should be made. For example, therate-of-change in the SOH is compared to a first threshold foridentifying a severity level. Based on a severity level, additionalinformation may be needed to further assess the SOH and time-to-failure.Under such conditions, the off-board diagnostic module 14 requestsadditional information from the vehicle 10 for generating a prognosis ofthe time-to-failure. The additional information may include operatingparameter data associated with the at least one component 15. Operatingparameter data may include, but is not limited to, snapshots of systemparameters such as signature fault information voltage, current,pressure, flow rates, additional SOH related data, DTCs, and parameteridentification data (PIDs). The off-board diagnostic unit 14 may selectwhich additional information should be provided from the vehicle 10.Therefore, the off-board diagnostic unit 14 receives only thatinformation that it deems pertinent for determining the time-to-failureof the component 15 as opposed to receiving non-essential data. Thethresholds may be generated based on history data and may be adaptivelymodified based on ongoing collected data. For example, for a newproduction vehicle, data may be extensively collected from the vehicleitself and/or collectively from a fleet of vehicles of the same modelvehicle for generating the baseline thresholds. After the baselinethresholds are established, data may be collected at a lesser rate fordetecting whether any shifts have occurred in the data (e.g., due toaging of the vehicle or increased mileage) which would require thatthresholds be adaptively modified. Moreover, the thresholds may beadaptively modified when taking into consideration past diagnoses wherefalse-positives and false-negatives occurred.

If the rate-of-change in the SOH is not of a severity level thatrequires additional information for assessing the time-to-failure of thecomponent 15, the SOH is compared to a second threshold. Under suchconditions, the off-board diagnostic module 14 determines whether thefrequency of the degradation signature provided by the on-boarddiagnostic module 10 should be increased. For example, the severitylevel does not warrant determining a time-to-failure; however, therate-of-change in the SOH shows signs of degradation for which the SOHshould be monitored more frequently that what is currently performed.Therefore, the frequency of the degradation signature as generated andreported to the off-board diagnostic unit 14 is increased. This may beperformed by shortening the interval between the transmissions of thedegradation signature or increasing a duty cycle at which thedegradation signature is provided.

If the rate-of-change in the SOH is not of a level that requires achange in the frequency of the reported degradation signature, then thesystem will continue to transmit the degradation signature at thecurrent transmission rate. This would indicate that the component 15 isoperating properly and degradation is as expected.

Alternatively, the on-board diagnostic unit 16 may autonomously transmitthe degradation signature if the on-board diagnostic unit 16 determinesthat the degradation signature is severely degraded beyond a respectiveoperating threshold. In such a case, it is unwarranted to wait until thetiming event occurs; rather, due to the severity of the degradationsignature as determined by the on-board diagnostics, the degradationsignature is transmitted immediately.

Referring to the condition where the severity level requires additionaldata, after receiving the additional information and determining atime-to-failure, the time-to-failure is communicated to the user of thevehicle using a respective mode of communication 32. The mode ofcommunication 32 may include, but is not limited to, cell phonecommunication 34, internet-based communications 36, or any otherwireless communication 38. Moreover, notification to the user of thetime-to-failure may be communicated through a third party such asdealership service department. In block 39, the information is output tothe user using an output device or vehicle interface device.

FIG. 2 illustrates a flowchart of a method for predicting atime-to-failure. In step 40, parameter data is collected by the vehicle.Sensors and other devices monitor the vehicle operating conditions for acomponent, subsystem, and system.

In step 41, the parameter data is collected and stored in a memorystorage device. The memory storage device may be integral to theon-board diagnostic unit, may be an independent vehicle-based storagedatabase separate from the on-board diagnostic unit, or may be a sharedstorage database.

In step 42, a degradation signature of the monitored component isdetermined.

In step 43, a determination is made whether the degradation signature isless than an operating threshold. If the degradation signature is lessthan an operating threshold, then degradation signature is immediatelytransmitted to the off-board diagnostic unit in step 44. If thedegradation signature is greater than an operating threshold, then theon-board diagnostic unit communicates the degradation signature to theoff-board diagnostic unit upon the occurrence of the triggered conditionin step 45. It should be understood that the degradation signature maybe determined by the on-board diagnostic system more frequently than thescheduled transmission based on the triggered condition.

In step 46, the off-board diagnostic unit receives the degradationsignature and determines the SOH of the monitored device. The off-boarddiagnostic unit determines a rate-of-change in the SOH based on thecumulative SOH stored in the off-vehicle storage database. Therate-of-change may be based off of any number of SOH determinationsmaintained in the storage database. For example, the rate-of-change maybe based on the last two SOH determinations, or may be based a selectnumber of SOH determinations within a respective time frame, or mayinclude the entire history of SOH determinations maintained in thestorage database for the monitored component

In step 47, the off-board diagnostic unit compares the rate-of-change inthe SOH to a first threshold. If the rate-of-change is less than thefirst threshold, then a determination is made that the rate-of-changehas degraded but not to a severity level that requires that atime-to-failure be generated. In response to the rate-of-change beingless than the first threshold, the routine proceeds to step 48.

In step 48, a determination is made whether the rate-of-change in theSOH is less than a second threshold. If the determination is made thatthe rate-of-change is less than the second threshold, then the routineproceeds to step 49 where no modifications are made in the monitoringprocess. This indicates that the component is operating properly and noadjustments are made to the frequency at which the degradation signatureis transmitted. If the determination is made that the rate-of-change inthe SOH is not less than the second threshold, then the routine proceedsto step 50.

In step 50, in response to the determination that the rate-of-change inthe SOH is not less than the second threshold, the trigger condition ismodified. This may include modifying the frequency at which thedegradation signature is transmitted to the off-board diagnostic unit.Modifying the frequency may include increasing the duty cycle time atwhich the degradation signature is transmitted or changing the eventwhich provides increases the rate at which the degradation signature istransmitted. For example, if the degradation signature is determinedevery ten ignitions starts, then the frequency may be changed to everyfive ignition starts.

Referring again to step 47, if the rate of change in the SOH is lessthan the first threshold, then the routine proceeds to step 51. In step51, a determination is made that the SOH has degraded significantlywhere additional analysis of the operating condition of the component isrequired beyond that of the degradation signature is provided by theon-board diagnostic unit, and the off-board diagnostic unit requestsadditional information from the vehicle. The additional information iscommunicated through the telematics center. The additional informationmay include specific operating parameters relating to the operation ofthe component. The purpose of requesting specific parameters is to allowthe off-board diagnostic unit to analyze only that information that itdeems necessary to further assess the SOH of the component. Performing adata dump on non-essential information would create inefficiencies intransmitting the data if a large amount of data is transmitted and wouldresult in the processor sorting through the data for determining whichinformation is pertinent. Such inefficiencies create delays in itsassessment of the component, particularly if the SOH health for multiplecomponents is being assessed.

In step 52, a severity of the SOH is determined based on the additionaldata supplied by the vehicle.

In step 53, a fault model and diagnostic reasoner is utilized fordetermining the expected fault and root cause. In addition, trendanalysis from past history of failed components and other analyticaltools may be utilized to predict a time-to-failure.

In step 54, a time-to-failure is generated. The time-to-failure mayprovide the detailed information regarding the component, what thepotential cause of the fault is, and the expected remaining useful lifefor the component.

In step 55, the time-to-failure information is output to the user. Theinformation may be output utilizing various methods which include, cellphones, text messages, email, web-based communications, other wirelesscommunications, vehicle interface device, or through a dealershipnotification program. Moreover, the time-to-failure may be communicatedthrough the telematics center.

While certain embodiments of the present invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention as defined by the following claims.

What is claimed is:
 1. A cooperative diagnostic system for generating aprognosis of at least one component in a vehicle, the system comprising:an in-vehicle diagnostic unit determining a degradation signature of theat least one component each time an occurrence of a condition istriggered; and an off-vehicle diagnostic unit receiving the degradationsignature and determining a state-of-health of the at least onecomponent as a function of the degradation signature; wherein thedetermined degradation signature of the at least one component iswirelessly transmitted to the off-vehicle diagnostic unit upon theoccurrence of the triggered condition, the off-vehicle diagnostic unitdetermining a rate-of-change in the state-of-health of the at least onecomponent, the off-vehicle diagnostic unit determining whether therate-of-change in the state-of-health is greater than a threshold, theoff-vehicle diagnostic unit requesting additional information from thevehicle in response to the rate-of-change in the state-of-health beinggreater than the threshold, the additional information relating tooperating parameter data associated with the at least one component, theoff-vehicle diagnostic unit receiving the requested information andpredicting a time-to-failure of the at least one component.
 2. Thesystem of claim 1 wherein each determined state-of-health is stored inan off-vehicle diagnostic unit memory, wherein the off-vehiclediagnostic unit collectively analyzes the stored state-of-healthdeterminations for determining the rate-of-change in thestate-of-health.
 3. The system of claim 2 wherein the triggeredcondition includes a time-triggered condition, wherein the off-boarddiagnostic unit determines an increase in a frequency of the timedcondition based on a rate-of-change in the state-of-health being greaterthan a second threshold.
 4. The system of claim 3 wherein increasing thefrequency of the time triggered condition is based on an incrementalrate-of-change in the state-of-health between two state-of-healthdeterminations.
 5. The system of claim 3 wherein increasing thefrequency of the time triggered condition is based on an incrementalrate-of-change in the state-of-health between two consecutivestate-of-health determinations.
 6. The system of claim 3 whereinincreasing the frequency of the time-triggered condition is based on anincremental rate-of-change in the state-of-health between a plurality ofstate-of-health determinations.
 7. The system of claim 2 wherein thetriggered condition includes an event-triggered condition that is basedon an occurrence of an event.
 8. The system of claim 2 wherein theon-board diagnostic unit compares the determined degradation signatureto an operating threshold, and wherein diagnostic unit transmits thedetermined degradation signature to the off-board diagnostic unit inresponse to the determined degradation signature being greater than theoperating threshold.
 9. The system of claim 1 further comprising atelematics center, wherein messages from the vehicle are relayed to theon-board diagnostic unit.
 10. The system of claim 1 wherein thetelematics center relays messages from off-board diagnostic unit to thevehicle.
 11. The system of claim 1 wherein the off-vehicle diagnosticunit selects which additional information is requested from the vehicle.12. The system of claim 1 wherein the off-vehicle diagnostic unitutilizes a diagnostic reasoner for predicting the fault in the at leastone component and predicting the time-to-failure.
 13. The system ofclaim 1 wherein the off-vehicle diagnostic unit utilizes a fault modelfor predicting the fault in the at least one component and predictingthe time-to-failure.
 14. The system of claim 1 wherein the prognosisdetermined by the off-board diagnostic unit is output to a user of thevehicle.
 15. The system of claim 14 further comprising a texting devicefor outputting the prognosis to the user.
 16. The system of claim 14further comprising a cell phone for outputting the prognosis to theuser.
 17. The system of claim 14 further comprising a vehicle-basedoutput device for outputting the prognosis to the user.
 18. The systemof claim 14 wherein the prognosis is output using email.
 19. The systemof claim 14 wherein a third party outputs the prognosis to the user. 20.The system of claim 19 wherein the third party is a vehicle dealership.21. The system of claim 19 wherein the third party is a telematicscenter.